VERO Panel Examines Why Bovine Respiratory Disease Persists Despite Widespread Vaccination

Three leading experts in immunology and cattle production recently visited the Texas A&M College of Veterinary Medicine & Biomedical Sciences’ (VMBS) Veterinary Education, Research & Outreach (VERO) campus in Canyon, Texas, to explore one of the most persistent challenges in cattle health —bovine respiratory disease (BRD).

Hosted by the VERO research program, the March 24 panel discussion — titled “BRD: If Everyone Vaccinates, Why Is It Still A Problem?” — featured Dr. John Ellis of the University of Saskatchewan; Dr. Amelia Woolums of Mississippi State University; and Dr. John Richeson of West Texas A&M University and was moderated by Dr. Paul Morley, professor and director of research for the VERO program.

Together, they offered complementary perspectives on vaccine development, field application, and the biological complexity of BRD to explore why the disease remains a leading cause of illness, antimicrobial treatment, and death across cattle populations in North American despite widespread vaccination.

Panelists emphasized that one of the greatest challenges is less about whether vaccines work but how and when vaccines are used within real-world production systems.

“There’s a difference between the physical act of applying the vaccine; immunizing, or inducing a state of immunity; and clinical protection,” Ellis said. “Those are not always aligned.”

The discussion was designed to expand conversations that typically take place among researchers and bring those insights to a broader audience of veterinarians, producers, and industry professionals.

“We often have some of our best idea sessions informally at meetings,” Morley said. We thought it would be great to invite people into those conversations.”

Interest in the topic was strong, with over 500 people registering for the virtual event and more than 60 attending live. Participants represented a wide cross-section of the cattle industry, including veterinarians, producers, researchers, and members of the pharmaceutical and biologics sectors.

That level of engagement reflects the continued impact of BRD, which remains the leading cause of illness and death in beef cattle and a major driver of antimicrobial use, according to Morley.

“It’s the most common cause of illness and death in cattle raised for beef production,” he said. “As the panel title suggests, there’s published data and a perception that the vaccines don’t help perform as expected under current field conditions.”

Panelists emphasized that while currently available vaccines can be effective, their performance often differs between controlled research settings and real-world production environments. Factors such as timing, animal movement, and varying management practices can all influence outcomes.

“I don’t think we have an immunization problem — I think we have a timing of immunization problem,” Richeson said.

In many cases, cattle are vaccinated at arrival to a new facility, when exposure has already occurred or is imminent, limiting the vaccine’s ability to provide protection.

The conversation also highlighted a central challenge facing the industry: balancing effective disease prevention with efforts to reduce antimicrobial use.

In practice, in the absence of other highly effective prevention methods, producers often must rely on antibiotics to manage BRD in high-risk cattle populations. This is made more difficult by the challenge of predicting which animals will become sick. While effective, this approach raises concerns about long-term antimicrobial stewardship.

Panelists also noted that BRD is not a single disease but a complex condition influenced by multiple pathogens and environmental factors.

“We’ve done a great job at creating vaccines for specific cattle pathogens,” Woolums said. “But with BRD, we’ve lumped a group of infections together and think we are going to control it by vaccinating targeted at five different organisms.”

At the same time, vaccination strategies alone have not consistently delivered the level of protection needed in current production systems.

“It’s not simple,” Morley said. “It’s extremely complex — it probably takes answers that move the system as opposed to just one simple thing.”

The panel reflects VERO’s broader mission to address the most pressing challenges in cattle health through research, collaboration, and outreach. By bringing together experts from across disciplines, the program aims to better understand complex diseases like BRD and identify more effective, sustainable solutions.

Following strong participation and positive feedback, organizers are exploring opportunities to expand the panel format into an ongoing series focused on other critical issues facing the cattle industry.

A recording of the panel discussion is available online for those who were unable to attend or would like to revisit the conversation.